CHAPTER VI 



Responses of Cells on the Biological Level 



Introduction 



It can be concluded from the previous chapters that 

 if the attempt is to be made to develop new drugs on a 

 rational basis, rather than on the hit or miss principle, 

 two types of research unit are required. One of these 

 types is necessary to study the general physico-chemical 

 properties of the cells of mammals and of parasites, in 

 particular such properties as permeability, secretion 

 mechanisms, excitability phenomena and adsorption 

 effects. The other type is more biochemical in character, 

 and is particularly required for the study of enzyme 

 effects. But this type of research in only a part of that 

 which can be deduced to be necessary from the cytological 

 point of view. There is also a great need for more frankly 

 biological studies of cells. Altogether too little is known of 

 what may, by analogy, be called the natural history and 

 ecology of cells, and their responses on the biological level. 



The Nature of Biological Responses 



The biological responses of cells to drugs are occasionally 

 highly specific and can only be elicited by a very small 

 Cell Physiology 8 



